Mining machines, such as longwall mining machines and continuous mining machines have a rotating cutter with a plurality of carbide inserts at the outer ends of the cutter which strike against the wall of the mine to loosen stone and coal for later removal. In the course of operating such equipment, the carbide inserts gradually wear away. Furthermore, the carbide inserts are braised into seats on supporting body members and on some occasions, the braising which retains the insert to the seat fractures, and the entire insert is lost. When a mining machine loses or breaks one or more of the carbide inserts, the machine will commence operating unevenly, will vibrate, and will cause stress to other portions of the machine, such that the machine must be shut down and repaired.
The carbide inserts of such machines are braised to removable bit bodies and, therefore, the removable body for which the carbide insert has been broken must be removed and replaced by a new or remanufactured body after which the machine can be placed back in service. To minimize the cost of maintenance of such machines, the bit bodies having damaged carbide inserts are remanufactured, during which the broken pieces of the prior carbide insert are removed, and a new carbide insert is attached.
In the course of the use of a bit body, the cutting end of the carbide insert will become worn. Worn carbide inserts can be reground without removing the insert from the body to which it is attached, but the grinding process also results in the grinding away of a portion of the body behind the distal end of the carbide. As a result, remanufactured bodies frequently do not provide support behind the entire length of the insert, and fracturing of the carbide insert is more common in remanufactured bodies.
Furthermore, prior art carbide inserts are braised to the seat of a body by visually positioning the carbide insert on the seat of the body and clamping the carbide insert in the desired location. The carbide insert is then braised to the seat of the body, after which the clamp is removed. The visual positioning of the carbide insert upon the seat of a body results in some misalignment of the insert upon the body. Where an insert has not been properly positioned and braised to a body, it will be subjected to uneven forces and the entire carbide insert may break away from the body. Approximately seven percent of the failure of all carbide inserts occurs as a result of breakage of the braising caused by the misalignment of the carbide insert.
It would, therefore, be desirable to provide a carbide insert for a mining machine which would be self centered upon the body during the braising process. Furthermore, it would be desirable to provide a carbide insert which is reinforced along its longitudinal length to reduce the failure of remanufactured bit bodies.